1. Field of the Invention
This invention relates, generally, to high speed sheet feeders. More particularly, it relates to a rocker plate that separates contiguous sheets from one another as they exit a sheet feeder bin and enter into a gate having a separator wheel.
2. Description of the Prior Art
U.S. Pat. No. 6,402,135 to the present inventor, entitled Sheet Feeder For Handling Sheets Of Varying Thickness, represents the prior art most relevant to the present invention. That patent discloses a large-in-diameter separator wheel and a shroud member having a first straight part, a curved second part having a radius of curvature that corresponds to the curvature of the separator wheel, and a second straight part.
The first straight part guides vertically stacked sheets in a bin as they descend to the bottom of the bin as sheets are sequentially removed from the bottom of the bin. The curved second part creates a stagger between contiguous sheets, and the third straight part is parallel to a conveyor that sequentially removes sheets from the bottom of the bin. A slot is formed in the second straight part to enable the sheets to be engaged by the separator wheel as said sheets are pulled from the bottom of the bin by the conveyor. The curvature of the shroud and the separator wheel cooperate to impart a stagger to the sheets. By varying the position of the separator wheel, sheets or articles of varying thickness may be dispensed at high speed from the bin. For example, items as thin as a single sheet of paper or as thick as a cassette tape can be dispensed.
In the prior art preceding U.S. Pat. No. 6,402,135, separate machines were required to handle thin items and thick items. Thus, the provision of the large-in-diameter separator wheel cut in half the cost of machinery required to operate a high speed paper-handling facility.
When a large number of items are stacked in a vertical bin, however, the pressure on the items at the bottom of the bin may create a frictional bond between contiguous items. Despite the curvature of the shroud, there are times when two or more items are bonded to one another by a frictional bond that does not break when the curvature is encountered.
There is a need, then, for a frictional bond-breaking means that separates items from one another at the bottom of the bend as they encounter the curvature of the shroud.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how such need could be fulfilled.